class_docstr: Data structure to store backdoor variables between 2 nodes.
code: def get_condition_vars(self):
      return self._condition_vars
  
imports: import networkx
  from dowhy.utils.graph_operations import adjacency_matrix_to_adjacency_list
label_desc: Use image node_id 3 for calling the NodePair obj's underlying member method code with example usage: obj.get_condition_vars() and returns: self